<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>群组选择器</title>
    <style>
        /* div{background-color: yellow;}
        p{background-color: yellow;}
        h1{background-color: yellow;} */

        /* div,p,h1{background-color: yellow;} */
        div,.boxp,h1{background-color: yellow;}
        /* 群组选择器：提出公共代码，节约代码量。注意每个元素选择符要以逗号隔开 */
    </style>
</head>
<body>
    <div>111111111111111
       
    </div>
    <p>2222222</p>
    <p class="boxp">11111111111111111</p>
    <h1>1111111111111</h1>
</body>
</html>